The /etc/ttytype file associates termcap(5)/terminfo(5) terminal type names with tty lines. Each line consists of a terminal type, followed by whitespace, followed by a tty name (a device name without the /dev/) prefix.
This association is used by the program tset(1) to set the environment variable TERM to the default terminal name for the user's current tty.
This facility was designed for a traditional time-sharing environment featuring character-cell terminals hardwired to a UNIX minicomputer. It is little used on modern workstation and personal UNIX systems.
the tty definitions file.
A typical /etc/ttytype is:
con80x25 tty1 vt320 ttys0
termcap(5), terminfo(5), agetty(8), mingetty(8)